1. Field of the Invention
The present invention relates generally to providing targeted disaster warnings to telephone subscribers in predetermined geographic areas.
2. Background of the Invention
Early warnings of natural (e.g., tornadoes) or man-made (e.g., leaks of toxic gases) disasters can save lives. However, any warning, no matter how timely, must be actually received by the people in danger, and must be heeded by the recipient if there is to be any benefit. Conventional systems for issuing disaster warnings may be directed to very large populations, for example, by radio or television, or may be directed to very small populations, for example, by people going house-to-house to notify the occupants. More recently, “weather radio” is being implemented to allow more localized warnings based on the listener's specific location.
However, all of these early warning systems have inherent disadvantages that reduce their effectiveness. For example, in the case of radio and television broadcasts, the television or radio sets must be turned on and monitored for the warning to be received. Moreover, it is not uncommon for the power systems in disaster zones to be out of operation, further limiting the likelihood that the target audience will receive the warnings. Finally, because television is designed to reach a maximum audience in a geographic region, it cannot currently be used to specifically target only those in the greatest danger. Thus, the warnings are sent to far more people than actually need to be warned. If people are often interrupted by alarms that do not apply to them, then they are less likely to heed subsequent warnings.
The “weather radio” system, when fully implemented, may overcome some of these limitations by issuing a radio signal to specially purchased radio receivers. The signal will cause the radio set to turn itself on and broadcast the warning to all listeners. However, even this solution has some disadvantages. First, the system is not in widespread use because it requires the purchase of a special radio receiver. Second, while weather radio can be directed toward a more specific geographic area than other broadcasting means, it cannot target very small regions, such as people located on a certain street. More people will receive the warning than are actually in danger, resulting in false alarms for many people. Thus, with weather radio systems, the result could be even more dangerous, as people who have been inconvenienced by false alarms may disable the feature or merely ignore further weather radio warnings.
When house-to-house personal warnings are issued, or neighborhood-wide announcements made via loud speakers, the deficiency is not in reaching the correct audience, but reaching them in time to provide sufficient early warning. Even if the target area is very small, if the danger stems from a rapidly moving force, such as a tornado, personal notification cannot provide the necessary early warning.